dunce79

This mean anything? Someone mentioned to me they thought maybe my heads had had some work done but I bought the engine as a pullout which had a Trex cam, Thunder Racing pushrods, LS6 intake and modified 4l60e. I haven't had the heads off so not sure whats up. Is that a normal stamping of some sort on there?

dunce79

A friend also thought maybe this wasn't a stock expansion plug?

1FastBrick

iTrader: (16)

That's a heat indicator. The glue will melt at a certain temp if the motor is over heated.

They use these when they provide a warranty. Either from the machine shop or from a junk yard.

Not sure on the heads. Clearly they were rebuilt but not sure if that is a a Stock rebuild Shop or Performance Shop or possibly an Engine Builder.